The major in vivo metabolites of S-(+)- and R-(-)-carvone in a metabolism of ingestion correlated amounts (MICA) experiment were newly identified as alpha,4-dimethyl-5-oxo-3-cyclohexene-1-acetic acid (dihydrocarvonic acid), alpha-methylene-4-methyl-5-oxo-3-cyclohexene-1-acetic acid (carvonic acid), and 5-(1,2-dihydroxy-1-methylethyl)-2-methyl-2-cyclohexen-1-one (uroterpenolone) on the basis of mass spectral analysis in combination with syntheses and NMR experiments. Minor metabolites were ...

Allium vegetables (onions, leeks, chives) and in particular garlic have been claimed to have health-promoting potential. This study was conducted to get insight into the perspectives for monitoring the intake of garlic by a biomarker approach. Chemically, the biomarker results from exposure to gamma-glutamyl-S-allyl-l-cysteine, which is first hydrolysed by gamma-glutamine-transpeptidase ...

The in vivo metabolic fate of 1,8-cineole was investigated in six male koalas. Koalas were fed ad lib a diet of Eucalyptus cephalocarpa leaf with a 1,8-cineole concentration of 2.53+/-0.70% dry mass of leaf, corresponding to a 1,8-cineole intake of 2.4+/-1.1 mmol/kg (3.1+/-1.3 g). Urine and faeces were collected for ...

A gas chromatographic-mass spectrometric method was developed for the quantitative analysis of the three Di(2-ethylhexyl)phthalate (DEHP) metabolites, 2-ethylhexanoic acid, 2-ethyl-3-hydroxyhexanoic acid and 2-ethyl-3-oxohexanoic acid in urine. After oximation with O-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine hydrochloride and sample clean-up with Chromosorb P filled glass tubes, all three organic acids were converted to their tert.-butyldimethylsilyl derivatives. ...

PURPOSE: To verify in an experimental model whether gastrocystoplasty may protect patients with chronic renal failure from acid loading associated acidosis a wedge-shaped portion of the middle stomach was used to improve bladder capacity in animals with chronic renal failure. MATERIALS AND METHODS: An experimental model was used to study ...

The agricultural fungicide N-(3,5-dichlorophenyl)succinimide (NDPS) induces nephrotoxicity in vivo that is characterized as acute polyuric renal failure and proximal tubular necrosis. However, earlier in vitro studies have failed to reproduce the in vivo nephrotoxicity seen with NDPS or its nephrotoxic metabolites N-(3,5-dichlorophenyl)-2-hydroxysuccinimide (NDHS) and N-(3,5-dichlorophenyl)-2-hydroxysuccinamic acid (2-NDHSA). The purpose of ...

Residues of 19-nortestosterone (19-NT) and diethylstilboestrol (DES) are excreted in bovine urine, mainly conjugated to glucuronic acid. Prior to quantification, urine must be deconjugated, which is commonly performed by enzymatic or chemical hydrolysis. The efficiencies of two enzymatic and two chemical deconjugation methods were studied. The range of efficiencies obtained ...

The efficacy of some putative attractants for the biting midge Culicoides impunctatus (Goetghebuer) (Diptera: Ceratopogonidae) was assessed using odour-baited 'delta traps' and suction traps. 1-octen-3-ol was confirmed as a potent olfactory attractant for C. impunctatus when released at 0.06mg/h. Acetone (23mg/h) and a mix of six phenolic compounds (phenol, 3-ethylphenol, ...

The enantiomeric separation of metoprolol and its metabolites in human urine was undertaken using capillary electrophoresis (CE). Resolution of the enantiomers was achieved using carboxymethyl-beta-cyclodextrin (CM-beta-CD) as the chiral selector. A 100-mM acetate buffer (pH 4.0) containing 5% 2-propanol and 10 mM CM-beta-CD resulted in the optimum separation of the ...

[5-3H, 1'-14C, 13C6, 12C] Indole-3-acetic acid (IAA), was applied to the flavedo (epicarp) of intact orange fruits at different stages of development. After incubation in the dark, at 25 degrees C, the tissue was extracted with MeOH and the partially purified extracts were analyzed by reversed phase HPLC-RC. Six major ...

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used as analgesic and anti-rheumatic drugs, and they are often misused. A gas chromatographic-mass spectrometric (GC-MS) screening procedure was developed for their detection in urine as part of a systematic toxicological analysis procedure for acidic drugs and poisons after extractive methylation. The compounds were ...

4-Heptanone is a common volatile constituent of human urine and is of unknown origin. We hypothesised that it arises from in vivo beta-oxidation of 2-ethylhexanoic acid (EHA) from plasticisers, similar to formation of 3-heptanone from valproic acid. We investigated urine from individuals with normal and increased plasticiser exposure. Using GC/MS, ...

BACKGROUND: Reversed-phase HPLC (RP-HPLC) has become an alternative to ion-exchange chromatography for amino acid analysis in biological fluids. However, validation studies for its urine application are limited, and the corresponding reference values have not been reported extensively. We studied the long-term performance of a commercial HPLC method for urine amino ...

Consumption of caffeine containing products is very popular in African children, particularly during ill health in the belief that caffeine promotes good health. This study aims to define the metabolism of caffeine, which takes place in the liver in a group of healthy Nigerian children. About 100 mg of caffeine ...

OBJECTIVES: To investigate in humans the contribution of the cytochrome P-450- and glutathione-dependent biotransformation of trichloroethylene (TRI) under controlled repeated exposure in volunteers, and under occupational conditions. METHODS: Volunteers were exposed to TRI, using repeated 15 min exposures at 50 and 100 ppm. This exposure schedule resulted in internal doses ...

A microplate enzyme immunoassay (EIA) was developed for the measurement of glycine- and taurine-conjugated 7alpha-hydroxy-3-oxo-4-cholenoic acids (CDCA-delta4-3-one) in human urine. The antiserum was prepared by immunizing rabbits with N-(7alpha-hydroxy-3-oxo-4-cholen-24-oyl)-3-aminopropionic acid--bovine serum albumin conjugate. A colorimetric EIA was established using horseradish peroxidase-labeled antigen having a shorter bridge length than that of ...

Omapatrilat, a potent vasopeptidase inhibitor, is currently under development for the treatment of hypertension and congestive heart failure. This study describes the plasma profile along with isolation and identification of urinary metabolites of omapatrilat from subjects dosed orally with 50 mg of [(14)C]omapatrilat. Only a portion of the radioactivity in ...

The metabolism of benzo[a]pyrene (BP) is known to lead to a large number of oxygenated compounds, some of which can bind covalently to DNA. We have studied the integrated metabolism of BP in vivo in germ-free rats given (14)C-labeled BP. Urinary metabolites were separated into groups according to acidity using ...

Epidemiological and toxicological studies often require the analysis of large numbers of samples for biological markers of exposure. The goal of this work was to develop a class-selective ELISA to detect groups of structurally closely related mercapturic acids with small nonpolar S-substituents. An assay was developed with strong recognition for ...

1. Radioactivity from oral doses of N-isopropyl[1-14C]acetanilide was excreted in urine (53.5%), faeces (8.1%) and expired air (17.0%) of rat. 2. Enterohepatic circulation occurred during formation of approximately 34% of the metabolites. N-isopropylacetanilide was metabolized by oxidation in all moieties of the molecule with subsequent conjugation with glucuronic and sulphuric ...

The metabolic profiles of three wild mammals that vary in their trophic strategies, the herbivorous bank vole (Clethrionomys glareolus), the granivorous wood mouse (Apodemus sylvaticus), and the insectivorous white-toothed shrew (Crocidura suaveolens), were compared with that of a widely used strain of laboratory rat (Sprague Dawley). In conjunction with NMR ...

To estimate pesticide exposure, urine samples are often needed to analyze pesticide metabolites. However, this is difficult for children wearing diapers because simple and feasible techniques suitable for field collection are not available. The objectives of this study were to test the validity of using cotton gauze pad as a ...

Species differences in the metabolism of acetylenic compounds commonly used in the formulation of pharmaceuticals and pesticides have not been investigated. To better understand the in vivo reactivity of this bond, the metabolism of propargyl alcohol (PA), 2-propyn-1-ol, was examined in rats and mice. An earlier study (Banijamali, A. R.; ...

1. The metabolic fate of 1,8-cineole was investigated in the brushtail possum. Six possums were fed an artificial diet to which 0.5% 1,8-cineole (wet weight) was added for 2 days. Urine and faeces were collected after the second day. A sample of each was extracted into ethyl acetate and analysed ...

An automated system for HPLC-fluorometry of serum guanidino compounds was constructed. This system accomplished simultaneous removal of protein and uremic fluorescences, abundant in the sera of uremic patients, which interfere with the fluorometric assay. This system was applied to the detailed elucidation of the behavior of guanidinosuccinic acid and methylguanidine ...

The goal of this study was to examine the usefulness of neurometabolic testing in patients with unexplained developmental delay. We included 118 patients from ages 3 months to 13 years. The evaluation was conducted according to a protocol that called for stepwise investigations with the intention to minimize unnecessary tests. ...

Eriocitrin, a flavonoid glycoside present in lemon fruit, is metabolized in vivo to a series of eriodictyol, methylated eriodictyol, 3,4-dihydroxyhydrocinnamic acid, and their conjugates. Plasma antioxidant activity increased following oral administration of aqueous eriocitrin solutions to rats. Eriocitrin metabolites were found in plasma and renal excreted urine through HPLC and ...

This study describes a fluorescent HPLC assay for measuring 20-hydroxyeicosatetraenoic acid (20-HETE) and other cytochrome P-450 metabolites of arachidonic acid in urine, tissue, and interstitial fluid. An internal standard, 20-hydroxyeicosa-6(Z),15(Z)-dienoic acid, was added to samples, and the lipids were extracted and labeled with 2-(2,3-naphthalimino)ethyl trifluoromethanesulfonate. P-450 metabolites were separated on ...

Three patients have been reported with (putative) methylmalonic semialdehyde dehydrogenase (MMSDH) deficiency. The urine metabolic pattern was strikingly different in all, including beta-alanine, 3-hydroxypropionic acid, both isomers of 3-amino- and 3-hydroxyisobutyric acids in one and 3-hydroxyisobutyric and lactic acids in a second, and mild methylmalonic aciduria in a third patient. ...

Reactive and hepatotoxic metabolites formed from the biotransformation of valproic acid (VPA) are normally detoxified by conjugating with GSH and followed by mercapturic acid metabolism to produce their respective N-acetylcysteine (NAC) conjugates. Hence, the levels of NAC conjugates of VPA in human urine are an indirect measure of exposure of ...

1. The metabolism and excretion of celecoxib, a specific cyclooxygenase 2 (COX-2) inhibitor, was investigated in mouse, rabbit, the EM (extensive) and PM (poor metabolizer) dog, and rhesus and cynomolgus monkey. 2. Some sex and species differences were evident in the disposition of celecoxib. After intravenous (i.v.) administration of [14C]celecoxib, ...

The metabolism of [2-acetyl-(14)C]oseltamivir (GS4104, Ro 64-0796), the prodrug of the novel influenza neuraminidase inhibitor GS4071 (Ro 64-0802), was examined in rats after oral dosing. Intact oseltamivir was observed only in lung and urine, accounting for 37 and 15% of the total radioactivity in these samples, respectively. GS4071 was the ...

Methods for the separation, identification, and quantitative assay of contaminants of L-tryptophan implicated in eosinophilia-myalgia syndrome (EMS) are described. Propylsulfonic acid (PRS), benzenesulfonic acid (SCX), and octyl-derivatized silica (C8) bonded-phase cartridges were used for the separation; LC-MS and GC-MS for identification; and HPLC-UV-fluorescence detection for quantitative analyses of norharman, harman, ...

Instability of beta2-microglobulin in acidic urine was investigated by identifying an associated protease from normal urine. Degradation was completely blocked by pepstatin, an aspartic protease inhibitor, and the counterpart of the inhibitor was thus sought. The molecular weight of the counterpart was similar to that of the inhibitor, while its ...

Gallic acid is one of the main phenolic components of black tea. The objective of this study was to identify urinary gallic acid metabolites with potential for use as markers of black tea intake. In an initial study, nine compounds, assessed by using gas chromatography-mass spectrometry, were found to increase ...

Urinary histamine and Ngamma-methylhistamine (1-MH), a histamine metabolite, are highly correlated with histamine in plasma. Therefore, allergic reactions can be examined by determination of histamine and 1-MH in urine. We separated histamine, 1-MH and Nalpha-methylhistamine (N-MH) by capillary electrophoresis with UV detection at 210nm, using borate buffer (pH 9) containing ...

Pyridinium chlorochromate (PCC) as an adulterant is popular for concealing drug-positive results. When 11-nor-delta9-THC-9-carboxylic acid (THC-acid) in urine was treated with 2 mmol/L of PCC (Cr6+ 104 microg/mL), 58-100% of the THC-acid was lost. The loss increased with decreasing pH and increasing reaction time (0-3 days). Free codeine and free ...

The amphetamine isomer ratios (l-amphetamine/d-amphetamine) in 373 urine specimens submitted for analysis over a two-year period have been determined using a chiral derivatizing agent in conjunction with a gas chromatograph fitted with a nitrogen-specific detector. All of the specimens were collected from known or suspected amphetamine abusers, some of which ...

A hand-saving HPLC method to measure urinary phenylmercapturic acid (PMA) was developed which allows about 35 PMA determinations per day. The method involves conversion of pre-PMA to PMA by the addition of sulfuric acid to a urine sample, extraction into an ether-methanol mixture followed by condensation under a nitrogen stream. ...

Isoxsuprine is routinely recovered from enzymatically-hydrolyzed, post-administration urine samples as parent isoxsuprine in equine forensic science. However, the specific identity of the material in horse urine from which isoxsuprine is recovered has never been established, although it has long been assumed to be a glucuronide conjugate (or conjugates) of isoxsuprine. ...

1. Nine habitual tea-drinking volunteers were recruited and asked to follow a low-polyphenol and low-caffeine diet for 6 days and to provide daily 24-h urine samples. On day 4 of the experiment strong black tea brewed under standardized conditions was re-introduced to the volunteers' diet. 2. 1H-NMR and HPLC profiling ...

Separation conditions in CE, with a neutral coated capillary and reversed polarity, have been optimised to make direct measurement of vanillylmandelic acid, homovanillic acid and 5-hydroxyindoleacetic acid possible in urine samples without pre-treatment. The method developed has been validated, presenting adequate parameters for linearity, accuracy and precision. Detection limits range ...

OBJECTIVES: Recently, S-phenylmercapturic acid (S-PMA) and trans,trans-muconic acid (t,t-MA) in urine have been proposed as reliable biomarkers for monitoring occupational exposure to benzene. The aim of this study was to test the applicability of S-PMA and t,t-MA as exposure biomarkers and to monitor the occupational exposure level and the extent ...

Biotransformation of styrene and its toxic metabolite, phenyloxirane (1), in mice in vivo was studied. Mice were treated with single intraperitoneal doses of styrene (400 mg/kg of body weight), and with (R)-, (S)-, or racemic styrene oxide (150 mg/kg of body weight). Profiles of neutral and acidic metabolites were determined ...